• Biodiversity can be measured at many scales
  • maintaining high biodiversity has huge benefits

• Conservation biology focuses on the population level
  • small populations have genetic problems

• Global Change is occurring at unprecedented rates
  • Yes, change has occurred over Earth’s history
  • No, it has never occurred this quickly

• Are we in a new mass extinction?

• Level 1: Genetic Diversity
  • within and among populations
  • loss of alleles reduces adaptive potential

• Level 2: Species Diversity
  • number of species in a system
  • local or whole extinctions possible
  • each species has a ‘role’ in the community

• Level 3: Ecosystem Diversity
  • variety of ecosystems on Earth
  • provide services to humans

• Genetic Diversity: alleles in populations
  • what happens when populations decline/disappear?

• Species Diversity
  • how many species?
  • how even are the species?
  • roles of dominant, keystone & rare species
  • are endemic species present?

• Ecosystem Diversity
  • what benefits do healthy ecosystems provide?
  • are the abiotic variables changing?

• Moral code: Each species belongs
  • what is the role of humans in causing, saving, or allowing extinction?

• Practical benefits for all 3 biodiversity types
  • genetic diversity a tool for medicines
  • diversity feeds, clothes and houses humans

• Ecosystem Services to humans
  • raw goods
  • health and well being
  • regulation of air, water, etc

• Human activities threaten biodiversity
  • at each scale

• Threats posed by humans fall into 4 categories

1. habitat loss
2. species introductions
3. over-harvesting
4. global change

• Landscape change is huge threat
  • land surfaces altered for human needs
  • causes fragmentation or loss of habitat

• Small populations are the most vulnerable
  • populations lose adaptive potential

• Small populations vulnerable to inbreeding
  • genetic issues of non-random mating

• Small populations vulnerable to genetic drift
  • chance loss of alleles

• Goal: Maintain genetic diversity to avoid extinction vortex

Declining Population Approach

• Detect downward trends in population sizes
  • may be a large population

• Prioritize the factors causing decline
  • habitat loss, climate change, etc.

• What are the environmental needs of the species?
  • What is the root cause of the decline?
  • How do we stop it?

• Global warming:

• Climate change:
  • more than just temperature
  • mostly related to post 1950’s

• Global change:
  • e.g. nutrient cycles, biodiversity, land use, sea level rise, ice loss

• Climate change is strongly related to the chemistry of the atmosphere
  • enhances existing greenhouse gas effect
  • CO₂, CH₄, NO_x & H₂O

• Greenhouse gases intercept and absorb radiation
  • more greenhouse gases = higher temperatures

• Burning of fossil fuels increases atmospheric CO₂
  • makes biosphere warmer
  • impacts weather and climate

• We cannot save all habitats
  • which patches are most crucial?

• Sustainable development
  • better engineer man-made ecosystems
  • food security while reducing environmental impacts of agriculture
  • food security while maintaining ecosystem services

• Curb global emissions
  • projected warming by end of century is uncertain
  • changes needed at individual, community and policy levels